Buildkite

1. Create new binary cache on https://app.cachix.org/cache and generate a write auth token.

2. Follow buildkite storing secrets in environment hooks tutorial to set $CACHIX_AUTH_TOKEN.

3. Replace mycache in the following .buildkite/pipeline.yml:

env:
  CACHE_NAME: mycache

steps:
  - label: "Set up Cachix"
    commands:
      - nix-env -iA nixpkgs.cachix
      - cachix use $CACHE_NAME
  - wait
  - label: "Build"
    commands:
      - cachix watch-exec $CACHE_NAME nix-build
      - cachix watch-exec $CACHE_NAME -- nix-shell --run "echo nix-shell successfully entered"